This is a phase-II, prospective, randomized, double-blind trial for subjects with 3 1,000 copies/ml of HIV RNA and 3 200 CD4 cells/mm3. All subjects will receive open-label induction therapy with zidovudine (ZDV), lamivudine (3TCTM) and indinavir for 6 months. Following this 6-month Induction Phase, subjects with undetectable plasma HIV RNA (by Roche Amplicor assay) at weeks 16, 20 and 24 will enter the Maintenance Phase and be randomized to one of three maintenance regimens. After 12 months of maintenance therapy, treatment will be withdrawn at 6-month intervals in randomly selected subjects who have achieved undetectable HIV RNA.